953 resultados para ALPHA-3-BETA-1 INTEGRIN
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Cellular Prion Protein (PrP(C)) is a cell surface protein highly expressed in the nervous system, and to a lesser extent in other tissues. PrP(C) binds to the extracellular matrix laminin and vitronectin, to mediate cell adhesion and differentiation. Herein, we investigate how PrP(C) expression modulates the aggressiveness of transformed cells. Mesenchymal embryonic cells (MEC) from wildtype (Prnp(+/+)) and PrP(C)-null (Prnp(0/0)) mice were immortalized and transformed by co-expression of ras and myc. These cells presented similar growth rates and tumor formation in vivo. When injected in the tail vein, PrnP(0/0)raS/myc cells exhibited increased lung colonization compared with Prnp(+/+)ras/myc cells. Additionally, Prnp(0/0)ras/myc cells form more aggregates with blood components than Prnp(+/+)ras/myc cells, facilitating the arrest of Prnp(0/0)ras/myc cells in the lung vasculature. Integrin alpha(v)beta(3) is more expressed and activated in MEC and in transformed Prnp(0/0) cells than in the respective Prnp(+/+) cells. The blocking of integrin alpha(v)beta(3) by RGD peptide reduces lung colonization in transformed Prnp(0/0) cells to similar levels of those presented by transformed Prnp(+/+) cells. Our data indicate that PrP(C) negatively modulates the expression and activation of integrin alpha(v)beta(3) resulting in a more aggressive phenotype. These results indicate that PrP(C) may have main implications in modulating metastasis formation. (C) 2009 UICC
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Objectives: To examine the effects of triiodothyronine (T(3)), 17 beta-estradiol (E(2)), and tamoxifen (TAM) on transforming growth factor (TGF)-alpha gene expression in primary breast cancer cell cultures and interactions between the different treatments. Methods and results: Patients included in the study (no.=12) had been newly diagnosed with breast cancer. Fresh human breast carcinoma tissue was cut into 0.3-mm slices. These slices were placed in six 35-mm dishes on 2-ml organ culture medium. Dishes received the following treatments: dish 1: ethanol; dish 2: T(3); dish 3: T(3)+TAM; dish 4: TAM; dish 5: E(2); dish 6: E(2)+TAM. TGF-alpha mRNA content was normalized to glyceraldehyde-3-phosphate dehydrogenase mRNA levels. All tissues included in this study were positive for estrogen receptor (ER) and thyroid hormone receptor expression. Treatment with T(3) for 48 h significantly increased TGF-alpha mRNA levels compared to controls (15-fold), and concomitant treatment with TAM reduced expression to 3.4-fold compared to controls. When only TAM was added to the culture medium, TGF-alpha mRNA expression increased 5.3-fold, significantly higher than with all other treatment modalities. Conclusion: We demonstrate that TGF-alpha mRNA expression is more efficiently upregulated by T(3) than E(2). Concomitant treatment with TAM had a mitigating effect on the T(3) effect, while E(2) induced TGF-alpha upregulation. Our findings show some similarities between primary culture and breast cancer cell lines, but also some important differences: a) induction of TGF-alpha, a mitogenic protein, by TAM; b) a differential effect of TAM that may depend on relative expression of ER alpha and beta; and c) supraphysiological doses of T3 may induce mitogenic signals in breast cancer tissue under conditions of low circulating E(2).. Endocrinol. Invest. 31: 1047-1051, 2008) (c) 2008, Editrice Kurtis
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The purpose of this study was to determine whether myofibroblasts or other cells in the stroma in the cornea produce interleukin (IL)-1 alpha or IL-1 beta that could modulate myofibroblast viability in corneas with haze after photorefractive keratectomy (PRK). Twenty-four female rabbits had haze-generating PRK for 9 diopters of myopia and were sacrificed at 1 week, 2 weeks, 3 weeks or 4 weeks after surgery. Corneal rims were removed, frozen in OCT at -80 degrees C, and analyzed by immunocytochemistry using primary antibodies to IL-1 alpha, IL-1 beta and alpha smooth muscle actin (SMA). Double immunostaining was performed for the co-localization of SMA with IL-1 alpha or IL-1 beta. Central dense haze and peripheral slight haze regions of each cornea were analyzed. SMA+ cells that expressed IL-1 alpha protein were detected in both regions of the corneas at most time points following PRK. However, in the haze region at the 1,3 and 4 week time points, significantly more (p < 0.01) SMA cells did not express IL-1 alpha. Also, in the haze region at all three time points, significantly more (p < 0.01) SMA- cells than SMA+ cells expressed interleukin-1 alpha protein. IL-1 beta expression patterns in SMA+ and SMA- stromal cells was similar to that of IL-1 alpha after PRK. Previous studies have demonstrated that IL-1 alpha or IL-1 beta triggers myofibroblast apoptosis in vitro, depending on the available concentration of apoptosis-suppressive TGFO. This study demonstrates that SMA- cells such as corneal fibroblasts, keratocytes, or inflammatory cells may produce IL-1 alpha and/or IL-1 beta that could act in paracrine fashion to regulate myofibroblast apoptosis-especially in the region where there is haze in the cornea after PRK was performed and SMA+ myofibroblasts are present at higher density. However, some SMA+ myofibroblasts themselves produce IL-1 alpha and/or IL-1 beta, suggesting that myofibroblast viability could also be regulated via autocrine mechanisms. (C) 2010 Elsevier Ltd. All rights reserved.
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Myocardial hypertrophy and dysfunction occur in response to excessive catecholaminergic drive. Adverse cardiac remodelling is associated with activation of proinflammatory cytokines in the myocardium. To test the hypothesis that exercise training can prevent myocardial dysfunction and production of proinflammatory cytokines induced by beta-adrenergic hyperactivity, male Wistar rats were assigned to one of the following four groups: sedentary non-treated (Con); sedentary isoprenaline treated (Iso); exercised non-treated (Ex); and exercised plus isoprenaline (Iso+Ex). Echocardiography, haemodynamic measurements and isolated papillary muscle were used for functional evaluations. Real-time RT-PCR and Western blot were used to quantify tumour necrosis factor alpha, interleukin-6, interleukin-10 and transforming growth factor beta(1) (TGF-beta(1)) in the tissue. NF-kappa B expression in the nucleus was evaluated by immunohistochemical staining. The Iso rats showed a concentric hypertrophy of the left ventricle (LV). These animals exhibited marked increases in LV end-diastolic pressure and impaired myocardial performance in vitro, with a reduction in the developed tension and maximal rate of tension increase and decrease, as well as worsened recruitment of the Frank-Starling mechanism. Both gene and protein levels of tumour necrosis factor alpha and interleukin-6, as well as TGF-beta(1) mRNA, were increased. In addition, the NF-kappa B expression in the Iso group was significantly raised. In the Iso+Ex group, the exercise training had the following effects: (1) it prevented LV hypertrophy; (ii) it improved myocardial contractility; (3) it avoided the increase of proinflammatory cytokines and improved interleukin-10 levels; and (4) it attenuated the increase of TGF-beta(1) mRNA. Thus, exercise training in a model of beta-adrenergic hyperactivity can avoid the adverse remodelling of the LV and inhibit inflammatory cytokines. Moreover, the cardioprotection is related to beneficial effects on myocardial performance.
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Interleukin (IL)-1 alpha and beta are important modulators of many functions of corneal epithelial and stromal cells that occur following injury to the cornea, including the influx of bone marrow-derived inflammatory cells into the stroma attracted by chemokines released from the stroma and epithelium. In this study, we examined the effect of topical soluble IL-1 receptor antagonist on bone marrow-derived cell influx following corneal epithelial scrape injury in a mouse model. C57BL/6 mice underwent corneal epithelial scrape followed by application of IL-1 receptor antagonist (Amgen, Thousand Oaks, CA) at a concentration of 20 mg/ml or vehicle for 24 h prior to immunocytochemical detection of marker CD11b-positive cells into the stroma. In two experiments, topical IL-1 receptor antagonist had a marked effect in blocking cell influx. For example, in experiment 1, topical IL-1 receptor antagonist markedly reduced detectible CD11b-positive cells into the corneal stroma at 24 It after epithelial injury compared with the vehicle control (3.5 +/- 0.5 (standard error of the mean) cells/400x field and 13.9 +/- 1.2 cells/400x field, respectively, p < 0.01). A second experiment with a different observer performing cell counting had the same result. Thus, the data demonstrate conclusively that topical IL-1 receptor antagonist markedly down-regulates CD-11b-positive monocytic cell appearance in the corneal stroma. Topical IL-1 receptor antagonist could be an effective adjuvant for clinical treatment of corneal conditions in which unwanted inflammation has a role in the pathophysiology of the disorder. (c) 2008 Elsevier Ltd. All rights reserved.
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Context: Berardinelli-Seip congenital lipodystrophy (BSCL) is a rare recessive disease characterized by near absence of adipose tissue, resulting in severe dyslipidemia and insulin resistance. In most reported cases, BSCL is due to alterations in either seipin, of unknown function, or 1-acylglycerol-3- phosphate acyltransferase-beta (AGPAT2), which catalyzes the formation of phosphatidic acid. Objective: We sought to determine the genetic origin of the unexplained cases of BSCL. We thus sequenced CAV1, encoding caveolin-1, as a candidate gene involved in insulin signaling and lipid homeostasis. CAV1 is a key structural component of plasma membrane caveolae, and Cav1-deficient mice display progressive loss of adipose tissue and insulin resistance. Design: We undertook phenotyping studies and molecular screening of CAV1 in four patients with BSCL with no mutation in the genes encoding either seipin or AGPAT2. Results: A homozygous nonsense mutation (p.Glu38X) was identified in CAV1 in a patient with BSCL born from a consanguineous union. This mutation affects both the alpha-and beta-CAV1 isoforms and ablates CAV1 expression in skin fibroblasts. Detailed magnetic resonance imaging of the proband confirmed near total absence of both sc and visceral adipose tissue, with only vestigial amounts in the dorsal sc regions. In keeping with the lack of adipose tissue, the proband was also severely insulin resistant and dyslipidemic. In addition, the proband had mild hypocalcemia likely due to vitamin D resistance. Conclusions: These findings identify CAV1 as a new BSCL-related gene and support a critical role for caveolins in human adipocyte function.
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Background and purpose: We investigated the effect of nitric oxide synthase (NOS) inhibition on polymorphonuclear cell (PMN) influx in zymosan or lipopolysaccharide (LPS)-induced arthritis and peritonitis. Experimental approach: Wistar rats received intra-articular (i.art.) zymosan (30-1000 mu g) or LPS (1-10 mu g). Swiss C57/Bl6 mice genetically deficient in intercellular adhesion molecule-1 (ICAM-1(-/-)) or in beta(2)-integrin (beta(2)-integrin(-/-)) received zymosan either i.art. or i.p. PMN counts, leukotriene B(4) (LTB(4)), tumour necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) levels were measured in joint and peritoneal exudates. Groups received the NOS inhibitors N(G)-nitro-L-arginine methyl ester (LN), nitro-L-arginine, N-[3-(aminomemethyl) benzyl] acetamide or aminoguanidine, prior to zymosan or LPS, given i.p. or s.c. in the arthritis and peritonitis experiments respectively. A group of rats received LN locally (i.art. or i.p.), 30 min prior to 1 mg zymosan i.art. Key results: Systemic or local NOS inhibition significantly prevented PMN migration in arthritis while increasing it in peritonitis, regardless of stimuli, concentration of NOS inhibitors and species. NOS inhibition did not alter TNF-alpha and IL-10 but decreased LTB(4) in zymosan-induced arthritis. LN administration significantly inhibited PMN influx into the joints of ICAM-1(-/-) and beta(2)-integrin(-/-) mice with zymosan-arthritis, while not altering PMN influx into the peritoneum of mice with zymosan-peritonitis. Conclusions and implications: Nitric oxide has a dual modulatory role on PMN influx into joint and peritoneal cavities that is stimulus-and species-independent. Differences in local release of LTB(4) and in expression of ICAM-1 and beta(2)-integrin account for this dual role of NO on PMN migration.
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Background and purpose: D-Fructose-1,6-bisphosphate (FBP) is an intermediate in the glycolytic pathway, exerting pharmacological actions on inflammation by inhibiting cytokine production or interfering with adenosine production. Here, the possible antinociceptive effect of FBP and its mechanism of action in the carrageenin paw inflammation model in mice were addressed, focusing on the two mechanisms described above. Experimental approach: Mechanical hyperalgesia (decrease in the nociceptive threshold) was evaluated by the electronic pressure-metre test; cytokine levels were measured by elisa and adenosine was determined by high performance liquid chromatography. Key results: Pretreatment of mice with FBP reduced hyperalgesia induced by intraplantar injection of carrageenin (up to 54%), tumour necrosis factor alpha (40%), interleukin-1 beta (46%), CXCL1 (33%), prostaglandin E(2) (41%) or dopamine (55%). However, FBP treatment did not alter carrageenin-induced cytokine (tumour necrosis factor alpha and interleukin-1 beta) or chemokine (CXCL1) production. On the other hand, the antinociceptive effect of FBP was prevented by systemic and intraplantar treatment with an adenosine A(1) receptor antagonist (8-cyclopentyl-1,3-dipropylxanthine), suggesting that the FBP effect is mediated by peripheral adenosine acting on A(1) receptors. Giving FBP to mice increased adenosine levels in plasma, and adenosine treatment of paw inflammation presented a similar antinociceptive mechanism to that of FBP. Conclusions and implications: In addition to anti-inflammatory action, FBP also presents an antinociceptive effect upon inflammatory hyperalgesia. Its mechanism of action seems dependent on adenosine production but not on modulation of hyperalgesic cytokine/chemokine production. In turn, adenosine acts peripherally on its A(1) receptor inhibiting hyperalgesia. FBP may have possible therapeutic applications in reducing inflammatory pain.
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Previously, it was demonstrated that the heme/heme oxygenase (HO)/carbon monoxide (CO) pathway inhibits neutrophil recruitment during the inflammatory response. Herein, we addressed whether the inhibitory effect of the HO pathway on neutrophil adhesion and migration involves the reduction of intracellular adhesion molecule type (ICAM)-1 and beta(2)-integrin expression. Mice pretreated with a specific inhibitor of inducible HO (HO-1), zinc protoporphyrin (ZnPP) IX, exhibit enhanced neutrophil adhesion and migration induced by intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS). These findings are associated with an increase in ICAM-1 expression on mesentery venular endothelium. In accordance, HO-1 inhibition did not enhance LPS-induced neutrophil migration and adhesion in ICAM-1-deficient mice. Furthermore, the treatment with a CO donor (dimanganese decacarbonyl, DMDC) that inhibits adhesion and migration of the neutrophils, reduced LPS-induced ICAM-1 expression. Moreover, neither DMDC nor ZnPP IX treatments changed LPS-induced beta(2)-integrin expression on neutrophils. The effect of CO on ICAM-1 expression seems to be dependent on soluble guanylate cyclase (sGC) activation, since 1H-(1,2,4)oxadiazolo (4,3-a)quinoxalin-1-one (sGC inhibitor) prevented the observed CO effects. Finally, it was observed that the nitric oxide (NO) anti-inflammatory effects on ICAM-1 expression appear to be indirectly mediated by HO-1 activation, since the inhibition of HO-1 prevented the inhibitory effect of the NO donor (S-nitroso-N-acetylpenicillamine) on LPS-induced ICAM-1 expression. Taken together, these results suggest that CO inhibits ICAM-1 expression on endothelium by a mechanism dependent on sGC activation. Thus, our findings identify the HO-1/CO/guanosine 3`5`-cyclic monophosphate pathway as a potential target for the development of novel pharmacotherapy to control neutrophil migration in inflammatory diseases.
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Ischemia and reperfusion injury (IRI) contributes to the development of chronic interstitial fibrosis/tubular atrophy in renal allograft patients, Cyclooxygenase (COX) 1 and 2 actively participate in acute ischemic injury by activating endothelial cells and inducing oxidative stress. Furthermore, blockade of COX I and 2 has been associated with organ improvement after ischemic damage. The aim of this study was to evaluate the role of COX I and 2 in the development of fibrosis by performing a COX I and 2 blockade immediately before IRI We subjected C57BI/6 male mice to 60 min of unilateral renal pedicle occlusion, Prior to surgery mice were either treated with indomethacin (IMT) at days -1 and 0 or were untreated. Blood and kidney samples were collected 6 wks after IRI. Kidney samples were analyzed by real-time reverse transcription-poly me rase chain reaction for expression of transforming growth factor beta (TGF-beta), monocyte chemoattractant protein 1 (MCP-1), osteopontin (OPN), tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-1 beta, IL-10, heme oxygenose 1 (HO-1), vimentin, connective-tissue growth factor (CTGF), collagen 1, and bone morphogenic protein 7 (BMP-7), To assess tissue fibrosis we performed morphometric analyses and Sirius red staining. We also performed immunohistochemical analysis of anti-actin smooth muscle, Renal function did not significantly differ between groups. Animals pretreated with IMT showed significantly less interstitial fibrosis than nontreated animals. Gene transcript analyses showed decreased expression of TGF-beta, MCP-1,TNF-alpha, IL-1-beta, vimentin, collagen 1, CTGF and IL-10 mRNA (all P < 0.05), Moreover, HO-I mRNA was increased in animals pretreated with IMT (P < 0.05) Conversely, IMT treatment decreased osteopontin expression and enhanced BMP-7 expression, although these levels did rot reach statistical significance when compared with control expression levels, I he blockade of COX 1 and 2 resulted in less tissue fibrosis, which was associated with a decrease in proinflammatory cytokines and enhancement of the protective cellular response.
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The title compound (3) has been synthesized and its presence sought in the urinary metabolites of the brushtail possum. © CSIRO 2001
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One-pot template condensation of CCl3C=N with ammonia on a metal source [MnCl2 center dot 4H(2)O, FeCl3 center dot 6H(2)O or Co(CH3COO)(2)center dot 4H(2)O] in DMSO led to the formation of tris(2,4-bis(trichloromethyl)-1,3,5-triazapentadienato)-M(III) complexes, [M(NH=C(CCl3)NC(CCl3)=-NH}(3)]center dot n(CH3)(2)SO [M = Mn, n = 1 (1); M = Fe, n = 2 (2); M = Co, n = 2 (3)1, which were characterized using elemental analysis, and IR, ESI-MS and single-crystal X-ray analysis. The role of inter- and intramolecular non-covalent halogen and hydrogen bonds in the synthesis of 1-3 is discussed. It is shown that the crystal ionic radii of the metal ions [68.5 (Co) < 69 (Fe) < 72 (Mn), pm] are related to the corresponding Cl center dot center dot center dot Cl distances [3.178 (3) > 3.155 (2) > 3.133 (1) Al. Compounds 1-3 and the related di(triazapentadienato)-Cu(v) complex [Cu(NH=C(CCl3)NC(CCl3)=NH}2]center dot 2(CH3)(2)SO (4) act as catalyst precursors for the additive-free microwave (MW) assisted homogeneous oxidation of 1-phenylethanol with tert-butylhydroperoxide (TBHP), leading to the formation of acetophenone with yields up to 99% and TONs up to 5.0 x 10(3) after 1 h of low power (10 W) MW irradiation.
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To study the role of CD8 beta in T cell function, we derived a CD8 alpha/beta-(CD8-/-) T cell hybridoma of the H-2Kd-restricted N9 cytotoxic T lymphocyte clone specific for a photoreactive derivative of the Plasmodium berghei circumsporozoite peptide PbCS 252-260. This hybridoma was transfected either with CD8 alpha alone or together with CD8 beta. All three hybridomas released interleukin 2 upon incubation with L cells expressing Kd-peptide derivative complexes, though CD8 alpha/beta cells did so more efficiently than CD8 alpha/alpha and especially CD8-/- cells. More strikingly, only CD8 alpha/beta cells were able to recognize a weak agonist peptide derivative variant. This recognition was abolished by Fab' fragments of the anti-Kd alpha 3 monoclonal antibody SF1-1.1.1 or substitution of Kd D-227 with K, both conditions known to impair CD8 coreceptor function. T cell receptor (TCR) photoaffinity labeling indicated that TCR-ligand binding on CD8 alpha/beta cells was approximately 5- and 20-fold more avid than on CD8 alpha/a and CD8-/- cells, respectively. SF1-1.1.1 Fab' or Kd mutation D227K reduced the TCR photoaffinity labeling on CD8 alpha/beta cells to approximately the same low levels observed on CD8-/- cells. These results indicate that CD8 alpha/beta is a more efficient coreceptor than CD8alpha/alpha, because it more avidly strengthens TCR-ligand binding.
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Tumor angiogenesis is an essential step in tumor progression and metastasis formation. Suppression of tumor angiogenesis results in the inhibition of tumor growth. Recent evidence indicates that vascular integrins, in particular alpha V beta 3, are important regulators of angiogenesis, including tumor angiogenesis. Integrin alpha V beta 3 antagonists, such as blocking antibodies or peptides, suppress tumor angiogenesis and tumor progression in many preclinical tumor models. The potential therapeutic efficacy of extracellular integrin antagonists in human cancer is currently being tested in clinical trials. Selective disruption of the tumor vasculature by high doses of tumor necrosis factor (TNF) and interferon gamma (IFN-gamma), and the antiangiogenic activity of nonsteroidal anti-inflammatory drugs are associated with the suppression of integrin alpha V beta 3 function and signaling in endothelial cells. Furthermore, expression of isolated integrin cytoplasmic domains disrupts integrin-dependent adhesion, resulting in endothelial cell detachment and apoptosis. These results confirm the critical role of vascular integrins in promoting endothelial cell survival and angiogenesis and suggest that intracellular targeting of integrin function and signaling may be an alternative strategy to extracellular integrin antagonists for the therapeutic inhibition of tumor angiogenesis.
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Purpose: Invasion and migration are key processes of glioblastoma and are tightly linked to tumor recurrence. Integrin inhibition using cilengitide has shown synergy with chemotherapy and radiotherapy in vitro and promising activity in recurrent glioblastoma. This multicenter, phase I/IIa study investigated the efficacy and safety of cilengitide in combination with standard chemoradiotherapy in newly diagnosed glioblastoma. Patients and Methods: Patients (age >= 18 to >= 70 years) were treated with cilengitide (500 mg) administered twice weekly intravenously in addition to standard radiotherapy with concomitant and adjuvant temozolomide. Treatment was continued until disease progression or for up to 35 weeks. The primary end point was progression-free survival (PFS) at 6 months. Results: Fifty-two patients ( median age, 57 years; 62% male) were included. Six- and 12-month PFS rates were 69% (95% CI, 54% to 80%) and 33% ( 95% CI, 21% to 46%). Median PFS was 8 months ( 95% CI, 6.0 to 10.7 months). Twelve- and 24-month overall survival ( OS) rates were 68% ( 95% CI, 53% to 79%) and 35% ( 95% CI, 22% to 48%). Median OS was 16.1 months ( 95% CI, 13.1 to 23.2 months). PFS and OS were longer in patients with tumors with O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation (13.4 and 23.2 months) versus those without MGMT promoter methylation (3.4 and 13.1 months). The combination of cilengitide with temozolomide and radiotherapy was well tolerated, with no additional toxicity. No pharmacokinetic interactions between temozolomide and cilengitide were identified. Conclusion: Compared with historical controls, the addition of concomitant and adjuvant cilengitide to standard chemoradiotherapy demonstrated promising activity in patients with glioblastoma with MGMT promoter methylation. J Clin Oncol 28:2712-2718. (C) 2010 by American Society of Clinical Oncology